“Jack had extensive wounds on the back of his body, and the wounds were unable to heal because his skin had deteriorated due to the malnutrition that occurred while he was lost,” the page’s administrator wrote.

“Despite antibiotics, the infections were worsening, and his skin was continuing to deteriorate. He needed surgery to treat the wounds, but there was not enough available skin to close the wounds after the surgery.”

Matthew Cooper of Blue Pearl Emergency Animal Hospital, after Jack was examined, said “He’s storing fat in his liver cells which is called hepatic lipidosis. That’s a pretty serious illness.”

American Airlines issued the following statement on their Facebook page:

“Jack was euthanized by the veterinarian today. We are deeply saddened that Jack the cat has passed away, and we offer profound sympathy to Jack’s owner, Karen Pascoe, for her loss. Our heart also goes out to the Friends of Jack and those in the cat-loving community who have grown fond of Jack since he went missing. We understand that a cat is a beloved family member for so many, including our own employees.

From all of us at American, our sincere apologies to Karen and Jack’s family and friends. We also thank all of you who have provided support, ideas, kindness and understanding for Jack along the way.”

Before boarding her flight in August, Jack’s owner Karen Pascoe received a call from airline employees telling her that Jack was missing. She boarded a different flight with her other cat, “Barry,” after an hour-long search for Jack came up empty.

According to an incident report, Jack and Barry were traveling in separate kennels. Baggage handlers had apparently stacked them on top of each other when Jack’s kennel fell allowing him to escape.

American Airlines made several efforts to find Jack including distributing posters throughout the airport, placing food and water throughout the terminal, setting up humane traps and issuing a pet AMBER alert.

Now that Jack has passed away, his loved ones wish to raise awareness of the risks of traveling with pets in cargo and inspire industry changes to make such travel safer for animals, according to Jack’s Facebook page’s administrator.

“We honor Jack, we honor all the other animals who have been killed, injured, or lost while being transported through cargo procedures, and we honor all of you who have taken the time to share your kindness and love with us.”